Today blood collection organizations routinely separate whole blood by centrifugation into its various therapeutic components, such as red blood cells, platelets, and plasma.
Conventional blood processing systems and methods use durable centrifuge equipment in association with single use, sterile processing chambers, typically made of plastic. The centrifuge equipment introduces whole blood into these chambers while rotating them to create a centrifugal field.
Whole blood separates within the rotating chamber under the influence of the centrifugal field into higher density red blood cells and platelet-rich plasma. The platelet-rich plasma is then further separated in a second stage into platelet concentrate and platelet-poor plasma.
Conventional wisdom believes that the processing volume for the second stage of separation should exceed the processing volume for the first stage. The larger processing volume is thought to give the platelets more time to separate, or sediment, from the platelet-rich plasma. The larger processing volume is also thought to protect the platelets from damage and activation due to shear stress during processing.